Which functional group characterizes alkanes?

Alkanes are characterized by having only single bonds between carbon atoms, making the presence of C-C single bonds the defining feature of this class of hydrocarbons. This is important because these bonds indicate that alkanes are saturated hydrocarbons, meaning they have the maximum number of hydrogen atoms attached to their carbon skeleton without any double or triple bonds.

Moreover, the C-H bonds present in alkanes contribute to their structure, but they do not solely define the class. The presence of only C-C single bonds differentiates alkanes from alkenes, which have at least one C=C double bond, and alkynes, which contain C≡C triple bonds. Understanding this distinction is crucial in organic chemistry, as it helps in identifying and classifying hydrocarbons based on their bonding structures.